algocpp::array::count

algocpp::array::count

Description

algocpp::array::count (hereafter count) is a function for fast counting of elements in an array.

Time

Assuming the number of elements is $N$

$O(N \log N)$

Example

#include <iostream>
#include <vector>
#include <algocpp/array.hpp>
using namespace std;

int main()
{
    vector<int> a = {1, 2, 3, 3};

    // 1
    cout << algocpp::array::count(a, 1) << endl;

    // 2
    cout << algocpp::array::count(a, 3) << endl;

    // 0
    cout << algocpp::array::count(a, 5) << endl;
}